The gastrointestinal tract (GIT) arises initially during the process of gastrulation from the endoderm of the trilaminar embryo (week 3) and extends from the buccopharyngeal membrane to the cloacal membrane. The tract and associated organs later have contributions from all the germ cell layers. Digestion is the breakdown of food into smaller particles or individual nutrients. It is accomplished through six basic processes, with the help of several body fluids—particularly digestive juices that are made up of compounds such as saliva, mucus, enzymes, hydrochloric acid, bicarbonate, and bile.

Enterohepatic circulation refers to the circulation of biliary acids, bilirubin, drugs, or other substances from the liver to the bile, followed by entry into the small intestine, absorption by the enterocyte and transport back to the liver. The mixture of organisms regularly found at any anatomical site is referred to as the normal flora, except by researchers in the field who prefer the term "indigenous microbiota”. The gastrointestinal mucosal immune system has the daunting task of coexisting with an incredibly complex mix of luminal antigens, including partially digested dietary constituents, host proteins, and commensal bacteria, while maintaining the capacity to recognize and eliminate pathogenic microbial organisms and transformed epithelial cells.

Functional gastrointestinal (GI) and motility disorders are common among children. Disorders like functional abdominal pain, chronic constipation and/or soiling, and irritable bowel syndrome (IBS) occur in children at a rate similar to adults. Diarrhoea is the body's way of ridding itself of germs, and most episodes last a few days to a week. Diarrhoea often occurs with fever, nausea, vomiting, cramps, and dehydration. Failure to thrive refers to children whose current weight or rate of weight gain is much lower than that of other children of similar age and gender.

GERD is a disorder of the lower esophageal sphincter muscle. This muscle keeps the stomach’s acid contents in place. If it is weak, or too relaxed, then it will not function properly, and the acid will travel up into the esophagus. Inflammatory bowel disease (which is not the same thing as irritable bowel syndrome, or IBS) refers to two chronic diseases that cause inflammation of the intestines: ulcerative colitis and Crohn's disease.

The aim of the pediatric practices is to reduce infant and child rate of deaths, control the spread of infectious disease, promote healthy lifestyles for a long disease-free life and help ease the problems of children and adolescents. It can be acknowledged that this can be reached by learning the major and primary subject on General Pediatrics.  Pediatrics includes the basic treatments involved for the betterment of pediatric health. The most significant problems can be due to nutritional deficiencies to the overall health of infants and children because growth and development can be seriously hindered by shortages in essential vitamins or nutrients.

Surgeons are continuing to improve their techniques for operating on colorectal cancers. They now have a better understanding of what makes colorectal surgery more likely to be successful, such as making sure enough lymph nodes are removed during the operation. Esophageal cancer  usually begins in the cells that line the inside of the esophagus. Pancreatic cancer begins in the tissues of your pancreas an organ in your abdomen that lies horizontally behind the lower part of your stomach. Colorectal cancer is cancer that starts in the colon or rectum. The colon and the rectum are parts of the large intestine, which is the lower part of the body’s digestive system. Anal cancer is an uncommon type of cancer that occurs in the anal canal. The anal canal is a short tube at the end of your rectum through which stool leaves your body. Gallbladder disease is relatively uncommon in the pediatric population, pediatric patients comprise a disproportionate number of cholecystectomies; this rate has been rising in recent years. Pediatric gallbladder disease is most commonly associated with haemolytic diseases. Stomach cancer is a disease in which malignant cancer cells form in the lining of the stomach.

Gastrointestinal defects  affect any part of your gastrointestinal tract. This includes the oesophagus that connects your mouth with your stomach, and your stomach to your intestines. Food travels through that tract after eating. Barrett's oesophagus is a condition where the cells of the oesophagus (gullet) grow abnormally. The biliary tract refers to the liver, gall bladder and bile ducts, and how they work together to make, store and secrete bile. Biliary disease often presents with upper abdominal pain. The pain quality is a penetrating aching or tightness, typically severe and located in the epigastrium.

The intestines are a long, continuous tube running from the stomach to the anus. Most absorption of nutrients and water happen in the intestines. The intestines include the small intestine, large intestine, and rectum. Stomach flu (enteritis): Inflammation of the small intestine. Infections (from viruses, bacteria, or parasites) are the common cause. The large intestine, also called the colon or the large bowel, is the last part of the digestive system in vertebrates. Water is absorbed here and the remaining waste material is stored as faeces before being removed by defecation. The liver is a large, meaty organ that sits on the right side of the bell. The liver's main job is to filter the blood coming from the digestive tract, before passing it to the rest of the body, Hepatitis: Inflammation of the liver, usually caused by viruses like hepatitis A, B, and C. The pancreas is about 6 inches long and sits across the back of the abdomen, behind the stomach. Systemic diseases in children are Antibiotic Therapy for Peritonitis, food poisoning.

Barium enema: lower bowel examination, barium enema is an X-ray test that allows your doctor to examine the lower part of your bowel. Barium swallow and barium meal tests: Both a barium swallow and a barium meal test involve a series of X-rays being taken of your upper digestive tract. Cholangiography: Cholangiography is an examination that uses X-rays and contrast medium (dye) to view your bile ducts. Cholecystography: Cholecystography is a procedure that helps to diagnose gallstones using X-rays and contrast medium to show up the gallbladder and bile duct. Coeliac disease: tests, find out about the tests used to diagnose coeliac disease. Colonoscopy: examination of the colon, a colonoscopy is an examination of the colon (large bowel), using a colonoscope a long, thin, flexible tube containing a camera and a light. Endoscopic retrograde cholangiopancreatography (ERCP): ERCP is an investigation used to view the gallbladder, bile ducts, pancreas and pancreatic duct. Endoscopy: In an endoscopy, a doctor looks down a thin lighted tube inserted into the body to see the internal structures. Faecal occult blood test: Faecal occult blood test is a chemical test that can detect tiny traces of blood in the stool that may indicate the presence of disease. Gallstones: diagnosis, several tests may be used in the diagnosis of gallstones, including blood tests, ultrasound and other imaging tests.Gastro-oesophageal reflux: tests and investigations, read about some of the tests used to diagnose and assess gastro-oesophageal reflux. Gastroscopy: examination of the upper digestive tract, gastroscopy is an examination of the upper digestive tract (the stomach and duodenum) using a long, thin, flexible tube with a camera.

Pediatric nutrition is the maintenance of a proper well-balanced diet consisting of the essential nutrients and the adequate caloric intake necessary to promote growth and sustain the physiologic requirements at the various stages of a child's development. Pediatric nutritional needs vary considerably with age, level of activity, and environmental conditions and they are directly related to the rate of growth. Breast Feeding has important ingredients that are not found in any infant formula, to build the baby’s immune system. Pediatric nutrition must consist of essential Vitamins and Minerals which help for the growth and development. Proteins are the basic units required mainly for the construction of the body muscles and in all the metabolic activities of the body. To increase the calcium levels intake of dairy products are needed.

Proton pump inhibitors reduce the production of acid in the stomach. This leaves little acid in the stomach juice so that if stomach juice backs up into the esophagus, it is less irritating. This allows the esophagus to heal. Antacid alkaline suspension is a drug combination that neutralizes gastric acidity and increases the pH of the stomach and duodenal bulb. Aluminium ions inhibit smooth muscle contraction and gastric emptying. Magnesium-aluminium antacid mixtures are used to avoid changes in bowel function. Gastric acid suppressants, in the form of histamine-2 receptor antagonists (H2RAs), have transformed the management of dyspepsia, peptic ulceration and gastro-oesophageal reflux disease.

A drug interaction can be defined as an interaction between a drug and another substance that prevents the drug from performing as expected. This definition applies to interactions of drugs with other drugs (drug-drug interactions), as well as drugs with food (drug-food interactions) and other substances.

EGD or upper endoscopy, this procedure allows the physician to examine the inside of the esophagus, stomach, and duodenum using a thin, flexible, lighted tube, called an endoscope. The endoscope is guided into the mouth and throat, then into the esophagus, stomach, and duodenum. Polypectomy of colonic polyps has been shown to reduce the risk of colon cancer development and is considered a fundamental skill for all endoscopists who perform colonoscopy. Endoscopicretrogradecholangiopancreatography (ERCP) is a technique that combines the use of endoscopy and fluoroscopy to diagnose and treat certain problems of the biliary or pancreatic ductal systems.

Hepatitis in children has many different origins or causes. A child may contract hepatitis from exposure to a viral source. The following is a list of some of the viruses associated with hepatitis: Hepatitis viruses. Five main types of the hepatitis virus have been identified, including hepatitis A, B, C, D, and E. Liver transplantation is a treatment, used in appropriately selected patients, for acute and chronic liver failure due to any cause. It is not indicated if an acceptable alternative is available or if contraindications are present.

Intussusception is the most common abdominal emergency affecting children under 2 years old. It happens when one portion of the bowel slides into the next, much like the pieces of a telescope. A hydrocele is a collection of fluid within the processus vaginalis (PV) that produces swelling in the inguinal region or scrotum. An inguinal hernia occurs when abdominal organs protrude into the inguinal canal or scrotum. Hirschsprung’s disease is a condition that affects the large intestine (colon) and causes problems with passing stool.

Imperforate anus is a defect that is present from birth (congenital). The opening to the anus is missing or blocked. The anus is the opening to the rectum through which stools leave the body. Intestinal malrotation, also known as intestinal nonrotation or incomplete rotation, refers to any variation in this rotation and fixation of the GI tract during development. Rectal and large intestinal atresia or stenosis is the term used to describe a group of rare congenital conditions of the lower gastro-intestinal tract (bowel).  Treating a child with multiple abdominal stomas can be intimidating and challenging, especially when the anatomy is not clear and the fluid and electrolyte abnormalities are difficult to control.

A pediatric physician is a specialist in the care of children and teens who are acutely ill or injured. He is trained to provide urgent care for a wide range of problems that require immediate medical help. These problems are often serious and may be life-threatening. Pediatric physician provides emergency and critical care by providing emergency drugs. Emergency drugs are those which are classified under this category because they are needed immediately, like in case of cardiac arrest and hypersensitivity. These dosages also should be designed and can only be taken with a proper guidance of a medical practitioner.